None.
In general, the present invention relates to a measuring apparatus. More particularly, the present invention relates to a combination square typically used in carpentry applications or other applications where layout or checking functions are performed. Most particularly, the present invention relates to a combination square having a pivoting head portion that allows the square to be used with radiused or otherwise irregular surfaces.
In carpentry, one of the most common and indispensable measuring tools is the square. Squares come in a number of varieties including L-shaped framing squares, triangular speed squares, and combination squares, among others. Each square, while performing the same basic function, generally has some advantage over others for particular applications. For example, a framing square, which generally consists of a long blade and a shorter, narrower tongue is useful for marking wide boards, checking the squareness of sheet stock, and laying out framing elements, such as rafter or stringers. A speed square is a right triangle and has a flange along its base which can be butt against the work piece edge allowing the user to rapidly draw or cut square or 45 degree lines. A combination square which includes a shorter handle-like leg, often referred to as a head, that slidably receives a blade is useful in laying out lines and transferring distances. The head has fences at 90 and 45 degrees that allows the user to quickly transfer a distance accurately and hold it while a line is drawn with a scribe or pencil. Often, the head is provided with a leveling bubble.
One difficulty that exists with using such squares occurs, when the edge of the work piece is not at a right angle to the surface on which markings or cuts are being made. For example, such irregular edges may be beveled or rounded such that very little of the fence can be placed against the surface. Often, due to the limited amount of contact between the fence and the work piece, the square tends to rock or slip because there is no corner to trap between the head and the blade.
In view of the foregoing, it is an object of the present invention to provide an improved combination square.
It is another object of the present invention to provide a combination square having a jointed head that allows rotation about an axis parallel to the blade permitting use of the combination square with irregular comers.
In view of at least one of the foregoing objects, the present invention generally provides a combination square comprising: a blade; and a head defining a slot in which said blade is at least partially received, said blade extending generally perpendicular to said head; wherein said head is divided into a first portion and a second portion, said first portion defining said slot, wherein said first and second portions are pivotally joined to each other by a pivot assembly, said pivot assembly defining an axis that extends parallel to said blade, whereby said second portion may be rotated about said axis.
The present invention further provides a combination square comprising: a blade; a head on which said blade is received, said head having a first fence extending generally perpendicular to said blade and a second fence extending at an angle relative to said blade, said head being divided into a first section and a second section pivotally jointed to each other about an axis, wherein said head includes a first pivot assembly at said first fence and a second pivot assembly adjacent said second fence and interiorly thereof; said first pivot assembly including a first tab extending downwardly from a first section of said head and a second tab extending upwardly from a second section of said head such that said tabs overlap each other and define a bore that extends through both of said tabs along said axis, and a pin received within said bore; and wherein said second pivot assembly includes a tab extending downwardly from said first portion and a sleeve formed on said second portion coaxially located with said tab, said sleeve and said tab defining a bore along said axis, said sleeve having a recess of a large dimension than said bore at one end defining a shoulder, a fastener having an enlarged end at one end and a threaded end at the opposite end insertably received within said bore, wherein said enlarged head portion of said fastener resides within said recess and is engagable with said shoulder to limit axial movement of said fastener, and a thumb screw threadably mounted on said threaded end of said fastener and rotatable thereon to selectively lock said second portion of said head in a selected position relative to said axis.